The map abuser likes to pick up the pipe

Sometimes it is enjoyable to abuse map. For example, it is possible to assign one scalar to another while using map statements as an intermediate pass through 'filter'.

This is a convienient typographical convention because you can 'chain' results together in a manner similar to 'pipes' in the Unix OS shell. This is useful because each step in the chain acts *in parallel* as an incremental and mutually substitutable filter. It is also useful because it allows you to both assign and modify a scalar in one statement.

The ugly side of map abuse

By its design, map is intended for use with arrays, not scalars. This design characteristic results in some fairly ugly artefacts in our code when we try to force map to do what we want.

• ugly0: parenthesis around the scalar used to invoke list context
• ugly1: special $_ variable tacked on just to get what we want out of map
• ugly2: scalar enclosed in a CODEREF to prevent it from being modified by map

my  $sBegin = "hello world";
my  $sEnd   = "";

($sEnd) =                           ### ugly0
    map{uc($_);}
    map{s/world/todo el mundo/;$_;} ### ugly1
    map{s/hello/goodbye/g;$_;}      ### ugly1
    (sub{$sBegin}->());             ### ugly0, ugly2

print $sEnd;
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